Eisenberg, Cumberland, and Spinrad (1998; Eisenberg, Spinrad, & Cumberland, 1998) included parent-child attachment as a key dimension of the early emotion socialization environment. We examined processes linking children's early attachment with social regulation and adjustment in preadolescence in 102 community mothers, fathers, and children. Security of attachment, assessed at 2 years, using observers' Attachment Q-Set (Waters, 1987), was posited as a significant, although indirect, predictor of children's adaptive social regulation at 10 and 12 years. We proposed that security initiated paths to future social regulation by promoting children's capacities for emotion regulation in response to frustration at 3, 4.5, and 5.5 years: having to suppress a desired behavior, observed in delay tasks, to regulate anger, observed in parent-child control contexts, and a traitlike tendency to regulate anger when frustrated, rated by parents. We conceptualized adaptive social regulation at 10 and 12 years as encompassing regulation of negative emotional tone, observed in diverse parent-child interactions, parent-rated regulation of negativity in broad social interactions, and child-reported internalization of adults' values and standards of conduct. Multiple-mediation analyses documented two paths parallel for mother- and father-child relationships: From security to emotion regulation in delay tasks to internalization of adults' values, and from security to parent-rated traitlike regulation of anger to parent-rated regulation of negativity in broad social interactions. Two additional paths were present for mothers and children only.